Source: http://www.telegraph.co.uk/news/2017/01/24/donald-trump-day-two-false-voter-fraud-claim-president-meets/ & http://www.nbcnews.com/politics/white-house/trump-sign-orders-advancing-keystone-dakota-access-pipelines-n711321
Trump wants the constructions to move forward and use domestically produced materials.
“The Trump administration’s politically motivated decision violates the law and the Tribe will take legal action to fight it,” said Archambault. “We are not opposed to energy independence. We are opposed to reckless and politically motivated development projects, like DAPL, that ignore our treaty rights and risk our water. Creating a second Flint does not make America great again.” (source)